WHAT LENS DO I NEED FOR A 4FTX5FT (Image circle of 68 inches or bigger)

[StoneNYC]

Have you ever seen an EKCo Ball Bearing Shutter that big? The video shows a mock-up, an ignorant artist's rendering, the same old fantasy to raise money that he's been doing for a couple of years.

I'm not going to sign up to another forum just to see pictures of the thing. BTW, the gigantic negs and prints from them that Manarchy has been showing around were taken with a room cam. Process lens in a wall between two rooms, sitter in one room, film holder in the other. Straight-on head shots of wrinkled old faces, some of which have stubble. Not what I'd hang on my wall, but tastes differ.

Unfortunately I can't see any of it with my phone, and I'm certainly not going to sign up to another website, however I would think that if you're building a very very large shutter, that you would do one that wasn't a leaf shutter, and was in fact a curtain shutter, that way you could have it on the vertical axis and simply use springs and gravity to carry fast along the line of film almost like a scanning back?

[jb7]

The only real answer to such a poorly defined question -

Any lens you want, as long as you accept that the image circle will be governed by the required magnification.

duh

[ebenostby]

You use a simple meniscus 2000mm lens from Surplus Shed (stock # L8093, $4.00), mount it in a tube, and stop it down to f/128 or smaller and have something better than a pinhole.
Or a pair of 4000mm lenses (L4639), mount them in a tube, symmetrically about a central stop, and have a periskop (symmetrical doublet lens).
Making the huge bellows would be an interesting challenge, wouldn't it? I'm pretty certain that the exposure time would be minutes, not fractions of a second, so a shutter could be a lens cap.

[E. von Hoegh]

...and to get such huge leaves to make 100th of a second - maybe a coffman engine starter would do it. Well, it's an amusing vision.

rotflmao!!

[Simon Liddiard]

What kind of quality do you believe a paper negative is gonna give?

Pretty good, judging by the direct positive Ilfochrome ultra-large work I've assisted with

http://en.wikipedia.org/wiki/Ilfochrome

____

The proposed use of Paper 'In itself' (*Instead of Film), is not going to be a 'Limiting Factor'... With respect to any said "Quality" -- In this situation or others.
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Photographic Papers 'in general' (B&W and almost always Color)... Are more than capable of resolving enough resolution (line pairs/per mm).
*Actually, the resolution of photographic papers is usually far greater than what is often considered as being required for a good 'Quality Print'... Which is to be observed by visual inspection (i.e. Resolution + Acutance).


http://www.largeformatphotography.in...-of-photopaper

http://ctein.com/PostExposure2ndIllustrated.pdf


Many years ago, there was a detailed article by Ctein in the March/April 2002 (Vol. 23, #2) issue of photo technique which was entitled... "Is Your Print Paper Sharp Enough?" -- That addressed this very subject question in greater detail.
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Is this what you were perhaps originally referring to?

There of course, are many other factors that can affect/determine the ultimate sharpness of a print... But the use of Paper (In itself) -- Is not usually one of them.
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Best regards,

-Tim.
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[Dan Fromm]

http://www.ebay.com/itm/Ultimate-lar...-/151162533287

Not mine, starting at only $4,750 and no bids yet. I wonder how high it will go. As has been mentioned, it won't meet the OP's needs as stated so far but its about the closest thing to the lens of his dreams.

[goamules]

I talked to the original poster weeks ago, and offered him advice. I respect his planning, and drive, he's been wanting to do this for years. And he's reaching out far and wide to find the best lens. From what I gathered, he's still hoping to find one fairly cheaply, so we moved on to other ideas, after briefly discussing my 1200mm Hermagis. I bet he will get something together, and we'll be hearing from him again before long.

[StoneNYC]

I talked to the original poster weeks ago, and offered him advice. I respect his planning, and drive, he's been wanting to do this for years. And he's reaching out far and wide to find the best lens. From what I gathered, he's still hoping to find one fairly cheaply, so we moved on to other ideas, after briefly discussing my 1200mm Hermagis. I bet he will get something together, and we'll be hearing from him again before long.

Maybe he should be the one posting... Or say thanks for all the helpful advice and close the thread then... Lol

[goamules]

I agree forums see this a lot; we are seen as personal oracles of knowledge, or places to step in for a quick WTB and purchase, then leave forever. But I said what I did because I think he's spending time doing, not talking about it. I think he'll report back.

[polyglot]

I would look into commissioning Reinhold to build one. I think someone linked to his website early in the thread but the OP might have passed over it because the lenses he offers by default aren't big enough. I bet he could make one though, perhaps even with a more-complex design (rectilinear or double-gauss) than his default meniscus lenses.